Coolant Drain Plug on Block...2012 / 5.3

[blondie70]

Howdy. Anyone know the size of the coolant drain plug? I can only see one on the drivers' side of the block. Appears to be a hex recessed type plug that needs a "giant allen wrench" to remove.
Next coolant flush, I want to remove it to make the flush a better one.
Thank you...Pete

 

[Big Mama]

I’ve never heard of it being done that way but I’m no mechanic. It seems a little dicey opening that up. A traditional flush should accomplish the same thing but I’ll be watching this thread to learn something new.

 

[strutaeng]

I bought this kit specifically for that plug. It's the largest or second from largest, so either 14mm or 17 mm.

3/8 in., 1/2 in. Drive Metric Hex Socket Set, 9 Piece

Amazing deals on this 9Pc 3/8In, 1/2In Dr Metric Hex Socket Set at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

My LQ4 I'm currently overhauling had a block heater installed there. I removed it and installed the brass plug (had one laying around from another engine teardown.)

Just reinstall it with thread sealant and torque it to spec. I think it's like 40 ft-lb, but don't quote me on that.

 

[Blackcar]

These Allen wrenches in link with ball end a lot of times let you remove hex plugs when obstructions are in the way of removing.

13-Piece Metric Ball End Hex Key Wrench Set | TEKTON | 25272

Includes: 1.27-10 mm (Metric) ball hex key wrenches. Up to 25-degree entry angle. Black oxide finish. Versatile long arm/short arm design. Hinged housing.

www.tekton.com

 

[Just Fishing]

I don't remember the size, but there is also one right above the starter (if memory serves me)
Otherwise you will have half of a block full of coolant.

When refilling, be careful of the thermostat.
if it's not one of those that have a little valve built in, they will trap air and not let it fill to the heads.
One of my neighbors blew an engine doing that.

 

[blondie70]

I don't remember the size, but there is also one right above the starter (if memory serves me)
Otherwise you will have half of a block full of coolant.

When refilling, be careful of the thermostat.
if it's not one of those that have a little valve built in, they will trap air and not let it fill to the heads.
One of my neighbors blew an engine doing that.

Hi Fishing.....wonder ...can one pull the plug above the starter without pulling the starter ? I looked up there and never saw a plug...Thanks for the info.

 

[Just Fishing]

Hi Fishing.....wonder ...can one pull the plug above the starter without pulling the starter ? I looked up there and never saw a plug...Thanks for the info.

I don't think you can, it's tight.

 

[blondie70]

I bought this kit specifically for that plug. It's the largest or second from largest, so either 14mm or 17 mm.

3/8 in., 1/2 in. Drive Metric Hex Socket Set, 9 Piece

Amazing deals on this 9Pc 3/8In, 1/2In Dr Metric Hex Socket Set at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

My LQ4 I'm currently overhauling had a block heater installed there. I removed it and installed the brass plug (had one laying around from another engine teardown.)

Just reinstall it with thread sealant and torque it to spec. I think it's like 40 ft-lb, but don't quote me on that.

Wow ! A kit just for one socket. Oh well ...maybe I'll make one....a piece of bar stock...a grinder and a stiltson wrench. What could go wrong ??? ha ha ha......thank you.

 

[strutaeng]

Wow ! A kit just for one socket. Oh well ...maybe I'll make one....a piece of bar stock...a grinder and a stiltson wrench. What could go wrong ??? ha ha ha......thank you.

Yeah, I bought that socket set because my other set didn't go that big.

So it's a 17 mm on that large one. I actually didn't remove the one near the starter side (I just painted over it too). I checked and that one is a 8 mm.

Photos for reference.

 

[j91z28d1]

I didn't realize the back starter side was 8mm. that's good to know.

 

[strutaeng]

I didn't realize the back starter side was 8mm. that's good to know.

Yeah. I was trying to think what would be in the way with the engine on the vehicle. I think the starter and the crank sensor connector need to be removed to access that one.

And I guess the large, 17 mm one is that large because it serves dual purpose: drain plug and block heater.

I guess I didn't realize (until now) these engines no longer have those older style "freeze plugs" or I guess technically core plugs. There's only a small one that style on the front near the pump, and gets covered by the front timing cover. All the rest are threaded. I like threaded.

 

[Big Mama]

You could also see if your local parts house has a tool loan program like Advance or Autozone.

 

[mikez71]

When refilling, be careful of the thermostat.
if it's not one of those that have a little valve built in, they will trap air and not let it fill to the heads.

My old boss had me drill a 1/8" hole topside of any thermostats that didn't have the jiggler valve.

 

[Just Fishing]

My old boss had me drill a 1/8" hole topside of any thermostats that didn't have the jiggler valve.

I have done that plenty of times, it works great.

 

[Big Mama]

Or used to remove the temp sensor plug on top of the intake.

 

[strutaeng]

I've actually had really good luck replacing things like water pumps and radiators on these trucks. Never had issues with air getting trapped. The way they designed the coolant system is pretty good (but I admit I really don't know how the system works with those little crossover pipes and all.) I just run the heater and air seems get released somehow on it's own.

Not long ago I replaced the thermostat on my wife's 3.6 pentastar minivan. After replacement, I couldn't get heat into the cabin. Had to watch a few YT videos and you have to open a bleeder to get the air out of the system on the thermostat. And the coolant that spills out does so directly on the belt, so soon afterwards the belt had to be replaced because it started chirping....

 

[Big Mama]

We had an E39 BMW that needed a burp once in a while. The engineers thought far enough ahead to put a small valve on the top of the motor. Smart.

 

[Blackcar]

We had an E39 BMW that needed a burp once in a while. The engineers thought far enough ahead to put a small valve on the top of the motor. Smart.

GM had those valves on 3800 and some LT1 in 90s worked very well.

 

[iamdub]

Wow ! A kit just for one socket. Oh well ...maybe I'll make one....a piece of bar stock...a grinder and a stiltson wrench. What could go wrong ??? ha ha ha......thank you.

I found a bolt and nut that fit that plug (5/8" head maybe?). I welded the nut to the bolt, inserted it into the plug and used a socket and ratchet to turn it.

 

[j91z28d1]

GM had those valves on 3800 and some LT1 in 90s worked very well.

I actually thought about adding those to the back steam ports on my ls3 car instead of buying a steam port kit.

never have, but seems easer and cleaner. Just open, bleed and tightne. done.